Pump unit for viscous liquids

ABSTRACT

A pump unit comprising a motor assembly including a motor provided with a first coupling element; an impeller assembly including a pump shaft and a second coupling element mounted on the pump shaft in complementary engagement with the first coupling element is described herein. The motor assembly is removably attached to the impeller assembly via the first and second coupling elements, the first and second coupling elements being so configured as to provide alignment thereof.

FIELD OF THE INVENTION

[0001] The present invention relates to a pump unit. More specifically, the present invention is concerned with a pump unit for viscous liquids having a removable and easy to replace section.

BACKGROUND OF THE INVENTION

[0002] Traditionally, pumping units employed in printing processes have proved to be a problem in cases of mechanical failures.

[0003] Indeed, conventional pump units usually incorporate a motor, which is securely mounted to an impeller assembly and to a reservoir cover plate, in such a way that it results difficult to reach certain components that may require maintenance or replacement. In particular, for the purpose of repairing or cleaning certain parts, the pump unit has to be disassembled into all of its components, which oftentimes results in a waste of time and added costs.

[0004] Efforts have been made by people in the art to resolve the difficulties noted above and design more convenient pump units. For example, U.S. Pat. No. 4,049,364, to Ross et al., discloses various possible coupling means between an impeller and the shaft of a motor in a centrifugal pump apparatus. One first such coupling means involves forming a groove in the shaft of the motor and providing a locator pin, which can move inwardly, laterally and outwardly of this shaft, and which can be seated within the groove on the motor shaft in such a way as to releasably secure the impeller with respect to the shaft of the motor, and to position the impeller in coaxial alignment with this shaft.

[0005] In spite of previous proposals such as the one mentioned above, there is obviously still a need for a pump unit that would be provided with a coupling means between the motor and the impeller assembly so designed as to allow an easy and rapid dismounting in times of cleaning or repairing.

OBJECTS OF THE INVENTION

[0006] An object of the present invention is therefore to provide an improved pump unit.

[0007] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.

SUMMARY OF THE INVENTION

[0008] More specifically, in accordance with the present invention, there is provided a pump unit comprising

[0009] a motor assembly including a motor provided with a first coupling element;

[0010] an impeller assembly including a pump shaft and a second coupling element mounted on said pump shaft in complementary engagement with said first coupling element; wherein said motor assembly is removably attached to said impeller assembly via said first and second coupling elements, said first and second coupling elements being so configured as to provide alignment thereof.

[0011] According to another embodiment of the present invention, there is provided a pump unit comprising an impeller assembly and a motor assembly:

[0012] said impeller assembly including:

[0013] a top member;

[0014] a bearing assembly having a bearing housing, a top bearing and a bottom bearing; said bearing housing having a flange so as to enable an adequate positioning of said bearing assembly to said top member;

[0015] a pump shaft having a proximate end provided with a second coupling member and a distal end to which is mounted an impeller; said pump shaft being associated with said bearings;

[0016] said motor assembly including

[0017] a motor having a driving shaft provided with a first coupling element;

[0018] a bearing cover mounted to said motor and having a flange so that said motor can be mounted to said top member by means of quarter turn fasteners;

[0019] wherein said first coupling element may be removably connected to said second coupling element so as to ensure a systematic and adequate alignment of said impeller assembly and said motor assembly.

[0020] According to a third embodiment of the present invention, there is provided a pump unit for ink reservoirs comprising:

[0021] a body including a top member, a bottom member and mounting elements therebetween;

[0022] a motor mounted to said top member,

[0023] an impeller housing removably mounted to said bottom member via quarter-turn fasteners; and

[0024] an impeller mounted in said impeller housing and operatively and removably connected to said motor; whereby said impeller housing may easily be disconnected from said bottom member.

[0025] According to a final embodiment of the present invention, there is provided a pump unit for ink reservoirs comprising:

[0026] a body including a top member, a bottom member and mounting elements therebetween;

[0027] a motor removably mounted to said top member via quarter-turn fasteners, and

[0028] an impeller assembly operatively and removably connected to said motor;

[0029] whereby said motor may easily be disconnected from said top member.

[0030] In the following, it is to be understood that a “quarter-turn fastener” refers to any fastener that may easily secure different mechanical parts together without the need of specialized tools, and without requiring many turns as is usually the case with conventional “machine screw” type fasteners.

[0031] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the appended drawings:

[0033]FIG. 1 is a perspective view of a pump unit for viscous liquids according to a first embodiment of the present invention, shown mounted to a reservoir;

[0034]FIG. 2 is an exploded view of the pump unit of FIG. 1;

[0035]FIG. 3 is a top plan view taken of the pump unit of FIG. 1;

[0036]FIG. 4 is a front elevational view of the pump unit of FIG. 1;

[0037]FIG. 5 is a side elevational view of the pump unit of FIG. 1.

[0038]FIG. 6 is a side elevational exploded view of a coupling assembly according to a second embodiment of a pump unit according to the present invention; and

[0039]FIG. 7 is an exploded view of the coupling assembly of FIG. 6, and of other elements of the pump unit.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040] Generally stated, the present invention aims at solving the above-mentioned problems encountered when a pump unit for viscous liquids, used for example with ink reservoirs employed in a printing press, needs to be repaired or cleaned.

[0041] The present invention provides an assembly for a pump unit that allows an easy and rapid dismounting, either for repairing or cleaning purposes for instance, or to refill the ink reservoirs in the case where the pump unit is used in a printing press.

[0042] FIGS. 1 to 5 of the appended drawings show a pump unit for viscous liquids according to a first embodiment of the present invention.

[0043] The pump unit 10 is shown installed in an ink reservoir 12 provided with a lid 14 and a bottom surface 16.

[0044] The pump unit 10 includes a motor assembly including a motor 18, an impeller assembly 20, and a fluid conduit 22.

[0045] The impeller assembly 20 includes a top member 24 and a base member 26, the top member 24 being mounted to the lid 14 of the ink reservoir 12 by means of machine screws 28 (see FIG. 2), and the base member 26 being mounted to an impeller housing 30 by means of quarter turn fasteners 32. The top 24 and base 26 members are separated and supported by mounting elements in the form of three support rods 34.

[0046] The impeller assembly 20 further includes a bearing assembly 46. The bearing assembly 46 comprises a pump shaft 48 (FIGS. 2 and 4), a bearing housing 52 (FIG. 4), and an impeller 54.

[0047] As for the motor 18, it has a substantially circular configuration. The motor assembly also includes a bearing cover 36 provided with a flange 38 allows the motor 18 to be mounted to the top member 24 of the impeller assembly 20 via quarter turn fasteners 40 as will be described hereinbelow.

[0048] The motor assembly also includes a male coupling element 42 (best seen in FIG. 4), mounted to the driving shaft (not shown) of the motor 18 and cooperating with a female coupling element 44 of the bearing assembly 46, as will be described hereinbelow.

[0049] The bearing assembly 46 is waterproof and is covered by the bearing cover 36. The pump shaft 48 has a proximate end provided with the female coupling element 44, and a distal end to which the impeller 54 may be mounted, as will be described hereinbelow.

[0050] As can be better seen from FIG. 4, the bearing assembly 46 includes a top bearing 56 and a bottom bearing 58, both mounted to the pump shaft 48 and protected by the housing 52. A flange 60 is provided on the housing 52 to correctly position the bearing assembly 46.

[0051] The distal end of the pump shaft 48 is provided with an externally threaded portion to which the impeller 54 may be mounted. Indeed, as can be seen from FIG. 2, the impeller 54 includes a central aperture 62 to which the externally threaded portion of the pump shaft 48 may be mounted.

[0052] The bearing housing 52 contributes to maintaining the spaced-apart relationship of the top and bottom bearings 56 and 58.

[0053] The support rods 34 (see FIG. 1) are screwed into the bottom member 26 and mounted to the top member 24 via fasteners 64.

[0054] As can be better seen in FIG. 2, the impeller housing 30 includes an ink inlet aperture 66 at the bottom thereof, and a sloped port 68 that guides the liquid or ink into the fluid conduit 22, then through a coupler 72 that is designed to be coupled to a conventional ink conduit of a printing press (not shown).

[0055] In operation, the starting of the motor 18 causes the rotation of the driving shaft (not shown) to which is attached the male coupling element 42. By virtue of the positive engagement of the male coupling element 42 in the cooperating female coupling element 44 of the pump shaft 48, there is a corresponding rotational movement of the pump shaft 48 and thus of the attached impeller 54.

[0056] The rotational movement of the impeller 54 causes, in turn, an inward flow of ink through the inlet aperture 66 of the impeller housing 30. The ink is then pumped upwardly through the sloped port 68, through both the fluid conduit 22 and the coupler 72 towards an inlet tube of the printing press (not shown).

[0057] When the pump unit 10 has to be repaired, the motor 18 is stopped. The reservoir lid 14 is lifted from the reservoir 12, taking the entire pump unit 10 along with it. Thereafter, the pump unit 10 is disassembled by first taking off the motor 18 by removing the quarter turn fasteners 40, thus exposing the bearing assembly 46. Then, the fasteners 32 mounting the base member 26 to the impeller housing 30 are unfastened to separate these two components and thus revealing the impeller 54. Subsequently, the impeller 54 is unscrewed from the pump shaft 48, enabling the pump shaft 48 to be repaired or replaced.

[0058] It is to be noted that the bearing assembly 46 and the shaft 48 may be fixedly mounted to one another to thereby enable those two elements to be replaced simultaneously.

[0059] When the pump unit 10 has been repaired, it is reassembled by doing the above steps essentially in reverse order. It is to be noted that the corresponding shape of the couplings 42 and 44 makes it possible to install the motor 18 without the need to align these couplings.

[0060] Turning now to FIGS. 6 and 7 of the appended drawings, a pump unit assembly 70 according to a second embodiment of the present invention will be described.

[0061] The main parts, shown in FIG. 7, are generally the same as those featured in FIG. 1. The pump unit 70 is installed in an ink reservoir provided with a lid and a bottom surface (not shown in FIG. 7). The pump unit 70 includes a motor 18, an impeller assembly 20, and a fluid conduit 22. The impeller assembly 20 includes a top member 24 and a base member (not shown) separated and supported by three support rods 34.

[0062] In the second embodiment shown in FIGS. 6 and 7, the proximal end of the driving shaft 71 of the motor 18 is provided with a driving gear 74, while the proximal end of the shaft 48 of the impeller assembly 20 is provided with a driven gear 76.

[0063] Both gears 74 and 76 are provided with teeth 78 on their circumference. To interconnect the driving and driven gears 74 and 76, the assembly 70 includes a double female coupling 75 that includes internal grooves 80 in an upper half 82 and internal grooves 84 in a lower half 86 thereof. These grooves are complementary with the teeth 78 of the driving and driven gears 74 and 76. In other terms, the driving gear 74 may be viewed as a first coupling element associated with the motor 18 and the assembly of the driven gear 76 and of the coupling 75 may be viewed as a second coupling element, associated with the impeller assembly and complementary with the first coupling element.

[0064] The driving gear 74, associated to the driving shaft 71 of the motor 18, is so sized as to engage into the upper half 82 of double female coupling 75; while the driven gear 76, associated with the pump shaft 48, is so sized as to engage into the lower half 86 of the double female coupling 75.

[0065] Once the driving gear 74 and the driven gear 76 are inserted into the double female coupling 75, the bearing cover 36 provided with a flange 38 slides down around the double female coupling 75 and around a bearing assembly 46 mounted on the top member 24. The bearing cover 36 is mounted on a base on the top member 24 of the impeller assembly 20 by means of quarter turn fasteners 40 inserted into the flange 38. Thus, the double female coupling 75 is encapsulated in an essentially waterproof manner.

[0066] It is to be noted that the grooves of both openings of the double female coupling 75 have a flaring out profile so as to allow the engagement of the gear 74 from the top, and the gear 76 from the bottom without having to carefully align them. Both gears are thus engaged smoothly within the double female coupling and the teeth 78 engage with ease within the complementary grooves 80.

[0067] When the pump unit 70 has to be repaired or cleansed, the motor 18 is first stopped. The reservoir lid is lifted from the reservoir 12 (as shown in FIG. 1), along with the entire pump unit 70. Thereafter, the quarter turn fasteners 40 are removed from the flange 38 so as to loosen the bearing cover 36 from the bearing assembly 46. The driving gear 74 can then be disengaged from the top-half of the female coupling 75 by lifting the motor 18. The female coupling 75 may then be disengaged from the driven gear 76.

[0068] The following steps are similar to those described in the above embodiment in accordance to FIG. 2: the fasteners 32 are unfastened so as to separate the base member 26 from the impeller housing 30, thus setting lose the impeller 54. Subsequently, the impeller 54 is unscrewed from the pump shaft 48 so as to proceed to repair or replacement of the pump shaft 48.

[0069] Once the pump unit 70 has been repaired or cleaned, it is readily reassembled by repeating the above steps in reverse order.

[0070] In this particular embodiment, the provision of driving gear 74 and driven gear 76, connected to the motor 18 and to the pump shaft 48 respectively, both provided with grooves 78 on their circumference, and of a the double female coupling 75, ensures a systematic and proper vertical alignment of the assembly, by engagement of the grooves 78 within the complementary grooves 80 provided in the interior surface of the double female coupling 75.

[0071] One skilled in the art will easily understand that the motor 18 can be hydraulically, pneumatically or electrically powered.

[0072] Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims. 

What is claimed is:
 1. A pump unit comprising a motor assembly including a motor having a driving shaft provided with a first coupling element; an impeller assembly including a pump shaft and a second coupling element mounted to said pump shaft in complementary engagement with said first coupling element; wherein said motor assembly is removably attached to said impeller assembly via said first and second coupling elements, said first and second coupling elements being so configured as to provide alignment thereof.
 2. A pump unit according to claim 1, wherein said impeller assembly also includes an impeller mounted to said pump shaft; when energized, said motor causing the rotation of said driving shaft and, by virtue of a positive engagement of said first coupling element and said second coupling element, causes a corresponding rotational movement of said pump shaft and of said impeller.
 3. A pump unit according to claim 1, wherein said first coupling element and said second coupling element have corresponding shapes that enable said motor assembly to be positioned without requiring an alignment of said first and second coupling elements.
 4. A pump unit according to claim 1, wherein said impeller assembly further comprises a bearing assembly associated with said pump shaft, and wherein said motor assembly further comprises a bearing cover provided with a flange, in such a way that said bearing cover surrounds said bearing assembly when said motor assembly is mounted to said impeller assembly.
 5. A pump unit according to claim 1, wherein said first coupling element includes a driving gear provided with teeth on the circumference thereof and mounted on a proximal end of said driving shaft, and said second coupling element includes a driven gear with teeth on the circumference thereof and mounted on a proximal end of said pump shaft of said impeller assembly, said first and said second coupling elements being connected by means of a double female coupling that has internal grooves complementary with said teeth of said driving and said driven gears, said grooves having a flaring out profile so as to allow engagement of said driving gear and said driven gear without needing a careful alignment.
 6. A pump unit according to claim 1, wherein said first coupling element including a male coupling mounted on a proximal end of said driving shaft, and said second coupling element includes a female coupling mounted on a proximal end of said pump shaft, said male coupling and said female coupling having cooperating shapes allowing engagement of said male coupling in said female coupling without needing a careful alignment.
 7. A pump unit according to claim 1, wherein said pump unit is used with an ink reservoir in a printing.
 8. A pump unit comprising an impeller assembly and a motor assembly: said impeller assembly including: a top member; a bearing assembly having a bearing housing, a top bearing and a bottom bearing; said bearing housing having a flange so as to enable an adequate positioning of said bearing assembly to said top member; a pump shaft having a proximate end provided with a second coupling member and a distal end to which is mounted an impeller; said pump shaft being associated with said bearings; said motor assembly including a motor having a driving shaft provided with a first coupling element; a bearing cover mounted to said motor and having a flange so that said motor can be mounted to said top member by means of quarter turn fasteners; wherein said first coupling element may be removably connected to said second coupling element so as to ensure a systematic and adequate alignment of said impeller assembly and said motor assembly.
 9. A pump unit according to claim 8, wherein said first coupling element includes a driving gear provided with teeth on the circumference thereof, and said second coupling element includes a driven gear with teeth on the circumference thereof, said first and said second coupling elements being connected by means of a double female coupling that has internal grooves complementary with said teeth of said driving and said driven gears, said grooves having a flaring out profile so as to allow engagement of said driving gear and said driven gear without needing a careful alignment.
 10. A pump unit according to claim 8, wherein said first coupling element includes a male coupling mounted on a proximal end of said driving shaft, and said second coupling element includes a female coupling mounted on a proximal end of said pump shaft, said male coupling and said female coupling having cooperating shapes allowing engagement of said male coupling in said female coupling without needing a careful alignment.
 11. A pump unit for ink reservoirs comprising: a body including a top member, a bottom member and mounting elements therebetween; a motor mounted to said top member, an impeller housing removably mounted to said bottom member via quarter-turn fasteners; and an impeller mounted in said impeller housing and operatively and removably connected to said motor; whereby said impeller housing may easily be disconnected from said bottom member.
 12. A pump unit according to claim 11, wherein said impeller housing is provided with a bottom surface having an ink inlet aperture and wherein said bottom member includes an outlet aperture; said impeller housing having a sloped port that guides a liquid through said outlet aperture, into a conduit and through a coupler.
 13. A pump unit according to claim 12, wherein said mounting elements include support rods.
 14. A pump unit for ink reservoirs comprising: a body including a top member, a bottom member and mounting elements therebetween; a motor removably mounted to said top member via quarter-turn fasteners, and an impeller assembly operatively and removably connected to said motor; whereby said motor may easily be disconnected from said top member. 